src/libloc.c

   1 /*
   2         libloc - A library to determine the location of someone on the Internet
   3
   4         Copyright (C) 2017 IPFire Development Team <info@ipfire.org>
   5
   6         This library is free software; you can redistribute it and/or
   7         modify it under the terms of the GNU Lesser General Public
   8         License as published by the Free Software Foundation; either
   9         version 2.1 of the License, or (at your option) any later version.
  10
  11         This library is distributed in the hope that it will be useful,
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14         Lesser General Public License for more details.
  15 */
  16
  17 #include <arpa/inet.h>
  18 #include <netinet/in.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <stdarg.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27
  28 #include <loc/libloc.h>
  29 #include <loc/private.h>
  30
  31 struct loc_ctx {
  32         int refcount;
  33         void (*log_fn)(struct loc_ctx* ctx,
  34                 int priority, const char *file, int line, const char *fn,
  35                 const char *format, va_list args);
  36         int log_priority;
  37 };
  38
  39 void loc_log(struct loc_ctx* ctx,
  40                 int priority, const char* file, int line, const char* fn,
  41                 const char* format, ...) {
  42         va_list args;
  43
  44         va_start(args, format);
  45         ctx->log_fn(ctx, priority, file, line, fn, format, args);
  46         va_end(args);
  47 }
  48
  49 static void log_stderr(struct loc_ctx* ctx,
  50                 int priority, const char* file, int line, const char* fn,
  51                 const char* format, va_list args) {
  52         fprintf(stderr, "libloc: %s: ", fn);
  53         vfprintf(stderr, format, args);
  54 }
  55
  56 static int log_priority(const char* priority) {
  57         char *endptr;
  58
  59         int prio = strtol(priority, &endptr, 10);
  60
  61         if (endptr[0] == '\0' || isspace(endptr[0]))
  62                 return prio;
  63
  64         if (strncmp(priority, "err", 3) == 0)
  65                 return LOG_ERR;
  66
  67         if (strncmp(priority, "info", 4) == 0)
  68                 return LOG_INFO;
  69
  70         if (strncmp(priority, "debug", 5) == 0)
  71                 return LOG_DEBUG;
  72
  73         return 0;
  74 }
  75
  76 LOC_EXPORT int loc_new(struct loc_ctx** ctx) {
  77         struct loc_ctx* c = calloc(1, sizeof(*c));
  78         if (!c)
  79                 return -ENOMEM;
  80
  81         c->refcount = 1;
  82         c->log_fn = log_stderr;
  83         c->log_priority = LOG_ERR;
  84
  85         const char* env = secure_getenv("LOC_LOG");
  86         if (env)
  87                 loc_set_log_priority(c, log_priority(env));
  88
  89         INFO(c, "ctx %p created\n", c);
  90         DEBUG(c, "log_priority=%d\n", c->log_priority);
  91         *ctx = c;
  92
  93         return 0;
  94 }
  95
  96 LOC_EXPORT struct loc_ctx* loc_ref(struct loc_ctx* ctx) {
  97         if (!ctx)
  98                 return NULL;
  99
 100         ctx->refcount++;
 101
 102         return ctx;
 103 }
 104
 105 LOC_EXPORT struct loc_ctx* loc_unref(struct loc_ctx* ctx) {
 106         if (!ctx)
 107                 return NULL;
 108
 109         if (--ctx->refcount > 0)
 110                 return NULL;
 111
 112         INFO(ctx, "context %p released\n", ctx);
 113         free(ctx);
 114
 115         return NULL;
 116 }
 117
 118 LOC_EXPORT void loc_set_log_fn(struct loc_ctx* ctx,
 119                 void (*log_fn)(struct loc_ctx* ctx, int priority, const char* file,
 120                 int line, const char* fn, const char* format, va_list args)) {
 121         ctx->log_fn = log_fn;
 122         INFO(ctx, "custom logging function %p registered\n", log_fn);
 123 }
 124
 125 LOC_EXPORT int loc_get_log_priority(struct loc_ctx* ctx) {
 126         return ctx->log_priority;
 127 }
 128
 129 LOC_EXPORT void loc_set_log_priority(struct loc_ctx* ctx, int priority) {
 130         ctx->log_priority = priority;
 131 }
 132
 133 LOC_EXPORT int loc_parse_address(struct loc_ctx* ctx, const char* string, struct in6_addr* address) {
 134         DEBUG(ctx, "Parsing IP address %s\n", string);
 135
 136         // Try parsing this as an IPv6 address
 137         int r = inet_pton(AF_INET6, string, address);
 138
 139         // If inet_pton returns one it has been successful
 140         if (r == 1) {
 141                 DEBUG(ctx, "%s is an IPv6 address\n", string);
 142                 return 0;
 143         }
 144
 145         // Try parsing this as an IPv4 address
 146         struct in_addr ipv4_address;
 147         r = inet_pton(AF_INET, string, &ipv4_address);
 148         if (r == 1) {
 149                 DEBUG(ctx, "%s is an IPv4 address\n", string);
 150
 151                 // Convert to IPv6-mapped address
 152                 address->s6_addr32[0] = htonl(0x0000);
 153                 address->s6_addr32[1] = htonl(0x0000);
 154                 address->s6_addr32[2] = htonl(0xffff);
 155                 address->s6_addr32[3] = ipv4_address.s_addr;
 156
 157                 return 0;
 158         }
 159
 160         DEBUG(ctx, "%s is not an valid IP address\n", string);
 161         return -EINVAL;
 162 }